'Maladaptive' or 'frustration' delinquency results from inadequate socialization in early life, and 'adaptive' or 'motivation' delinquency, which develops later, results from environmental stress and pressure. The authors urge that commitment of delinquent youths to an effective training school is the best method for reducing chronic delinquency, especially among boys. They also advocate that delinquents sent to training schools be actively encouraged to change their behavior to win early release, that juvenile crime penalties be predictable and prompt in order to act as deterrents, and that probation -- if administered swiftly and to the 'right' juveniles -- can be an effective penalty for juvenile delinquents. Photographs, an index, 108 references, appendixes are supplied. For related document, see NCJ 98223.